ext2文件系统源代码之ext2.h

#include <linux/fs.h>
#include <linux/ext2_fs.h>

/*ext2挂载选项结构体*/
struct ext2_mount_options {
/*挂载选项位图*/
unsigned long s_mount_opt;
/*保存用户id和保存组id*/
uid_t s_resuid;
gid_t s_resgid;
};

/*在内存里的ext2文件系统的inode信息数据*/
struct ext2_inode_info {
__le32	i_data[15];
__u32	i_flags;
__u32	i_faddr;
__u8	i_frag_no;
__u8	i_frag_size;
__u16	i_state;
__u32	i_file_acl;
__u32	i_dir_acl;
__u32	i_dtime;

/*i_block_group是这个文件的inode所在的块组号码，ext2文件系统分配block的时候尽量使得block和他的inode在一个块组，分配inode的时候尽量使得inode和它的父目录的inode在一个块组 */
__u32	i_block_group;

/*i_next_alloc_block记录最近分配的块的逻辑编号，这个名字取得不是很好 */
__u32	i_next_alloc_block;

/*i_next_alloc_goal记录最近分配的块的物理编号，这个变量给了我们下一次分配的优先位置*/
__u32	i_next_alloc_goal;
__u32	i_prealloc_block;
__u32	i_prealloc_count;
__u32	i_dir_start_lookup;
/*配置了CONFIG_EXT2_FS_XATTR宏才会有的属性操作的信号量*/
#ifdef CONFIG_EXT2_FS_XATTR
struct rw_semaphore xattr_sem;
#endif
/*配置了CONFIG_EXT2_FS_POSIX_ACL宏才会有的属性操作的acl操作结构体，之前讲过的哦*/
#ifdef CONFIG_EXT2_FS_POSIX_ACL
struct posix_acl	*i_acl;
struct posix_acl	*i_default_acl;
#endif
rwlock_t i_meta_lock;
/*我们一般用到的inode结构体就是这个*/
struct inode	vfs_inode;
};

/*ext2的标记位，这个标识ext2刚刚建立*/
#define EXT2_STATE_NEW			0x00000001 /* inode is newly created */

/*从inode结构体获得ext2_inode_info的函数，直接通过container_of宏，上边我们刚讲过，vfs_inode就是此处的inode*/
static inline struct ext2_inode_info *EXT2_I(struct inode *inode)
{
return container_of(inode, struct ext2_inode_info, vfs_inode);
}

/* balloc.c的函数声明，我们都讲过的哦 */
extern int ext2_bg_has_super(struct super_block *sb, int group);
extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group);
extern int ext2_new_block (struct inode *, unsigned long,
__u32 *, __u32 *, int *);
extern void ext2_free_blocks (struct inode *, unsigned long,
unsigned long);
extern unsigned long ext2_count_free_blocks (struct super_block *);
extern unsigned long ext2_count_dirs (struct super_block *);
extern void ext2_check_blocks_bitmap (struct super_block *);
extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
unsigned int block_group,
struct buffer_head ** bh);

/* dir.c的函数声明，我们都讲过的哦 */
extern int ext2_add_link (struct dentry *, struct inode *);
extern ino_t ext2_inode_by_name(struct inode *, struct dentry *);
extern int ext2_make_empty(struct inode *, struct inode *);
extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,struct dentry *, struct page **);
extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
extern int ext2_empty_dir (struct inode *);
extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **);
extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *);

/* fsync.c 的函数声明*/
extern int ext2_sync_file (struct file *, struct dentry *, int);

/* ialloc.c的函数声明 */
extern struct inode * ext2_new_inode (struct inode *, int);
extern void ext2_free_inode (struct inode *);
extern unsigned long ext2_count_free_inodes (struct super_block *);
extern void ext2_check_inodes_bitmap (struct super_block *);
extern unsigned long ext2_count_free (struct buffer_head *, unsigned);

/* inode.c的函数声明 */
extern void ext2_read_inode (struct inode *);
extern int ext2_write_inode (struct inode *, int);
extern void ext2_put_inode (struct inode *);
extern void ext2_delete_inode (struct inode *);
extern int ext2_sync_inode (struct inode *);
extern void ext2_discard_prealloc (struct inode *);
extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
extern void ext2_truncate (struct inode *);
extern int ext2_setattr (struct dentry *, struct iattr *);
extern void ext2_set_inode_flags(struct inode *inode);
extern void ext2_get_inode_flags(struct ext2_inode_info *);

/* ioctl.c的函数声明 */
extern int ext2_ioctl (struct inode *, struct file *, unsigned int,
unsigned long);
extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);

/* namei.c的函数声明 */
struct dentry *ext2_get_parent(struct dentry *child);

/* super.c的函数声明 */
extern void ext2_error (struct super_block *, const char *, const char *, ...)
__attribute__ ((format (printf, 3, 4)));
extern void ext2_warning (struct super_block *, const char *, const char *, ...)
__attribute__ ((format (printf, 3, 4)));
extern void ext2_update_dynamic_rev (struct super_block *sb);
extern void ext2_write_super (struct super_block *);

/*
* Inodes和files结构体的函数操作结构体集合
*/

/* dir.c文件里的*/
extern const struct file_operations ext2_dir_operations;

/* file.c文件里的 */
extern const struct inode_operations ext2_file_inode_operations;
extern const struct file_operations ext2_file_operations;
extern const struct file_operations ext2_xip_file_operations;

/* inode.c文件里的 */
extern const struct address_space_operations ext2_aops;
extern const struct address_space_operations ext2_aops_xip;
extern const struct address_space_operations ext2_nobh_aops;

/* namei.c文件里的 */
extern const struct inode_operations ext2_dir_inode_operations;
extern const struct inode_operations ext2_special_inode_operations;

/* symlink.c文件里的 */
extern const struct inode_operations ext2_fast_symlink_inode_operations;
extern const struct inode_operations ext2_symlink_inode_operations;